Brush holder and connector assembly



Feb. 16, 1965 K. P. SHETTERLY 3,170,030

BRUSH HOLDER AND CONNECTOR ASSEMBLY Filed March 30, 1961 F I 4 INVENTOR. Kar/ PSheHer/y (LEW His Attorney United States Patent 3,179,880 BRUSH HOLDER AND CQDNNECTGR ASSEMBLY Karl P. Shetterly, Anderson, Ind, assignor to General Motors Corporation, Detroit, Mich, a corporation of Delaware Filed Mar. 36, 196i, Ser. No. 99,446 7 Claims. (Cl. 31l-24$) This invention relates to brush shunt connections that electrically connect the brush and brush holder of a dynamoelectric machine and to its method of manufacture.

In dynamoelectric machines, it is common practice to provide a positive electrical connection between a brush of the machine and its brush holder even though the brush and brush holder are electrically connected in many instances by sliding engagement and usually by a spring that urgesthe brush toward the commutator. This connection takes the form of a conductor which is frequently called a brush shunt or pigtail. This brush shunt conductor is connected to the brush holder by means of a terminal that is fixed to the shunt conductor and is fixed to the brush holder by means of a screw fastener.

In contrast to the above described construction, it is an object of this invention to provide a brush shunt connection wherein the shunt conductor is welded to the brush holder and whereinmeans are provided for preventing stressing of the weld due to movement of the conductor.

A more specific object of this invention is to provide a brush shunt connection wherein both a terminal and a brush shunt conductor are welded to a brush holder and wherein the terminal prevents stressing of the weld.

Another object of this invention is to provide a method of making a welded connection between a brush shunt conductor and a brush holder, the steps comprising, fitting a terminal to a conductor that has a ferrule portion and a flat portion, placing the flat portion of the terminal and the attached brush shunt conductor on a portion of the brush holder, and then passing a welding current through the flat portion of the terminal, through the brush shunt conductor and through a portion of the brush holder.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings wherein preferred embodiments of the present invention are clearly shown.

In the drawings:

FIGURE 1 illustrates one of the steps in providing the welded brush shunt connection of this invention.

FIGURE 2 illustrates a brush shunt conductor after it has been fitted to a terminal.

FIGURE 3 illustrates a method of forming a welded brush shunt connection in accordance with this invention.

FIGURE 4 is a view illustrating the brush holder with its attached brush shunt connection in place in a dynamoelectric machine.

FIGURE 5 illustrates a modified arrangement for providing a welded connection between a brush shunt conductor and a brush holder.

Referring now to the drawings and more particularly to FIGURE 2, the reference numeral designates a conventional brush which is connected with a brush shunt conductor 12. It is desired to connect the brush shunt conductor 12 to a brush holder which is generally desig nated by reference numeral 14 in the drawings. The brush holder 14 has sidewalls 16 and 18 which provide a rectangular chamber that receives the brush 10. The brush holder 14 also has arcuately extending portions 20 and 22, the portion 22 being the part to which the brush shunt conductor 12 is welded.

3,170,080 Patented Feb. 16,1965

In making the welded connection between the brush shunt conductor 12 and the metal brush holder 14, the

brush shunt conductor 12 is first fitted to a terminal memher which is generally designated by reference numeral 24. This terminal member has a ferrule section 26 which initially has a wider opening at the end 28 than at the vthe conductor portion 12 and after crimping, the ferrule portion is as is shown in FIGURE 2. It is noted that the nd 28 is not crimped in so that there is some clearance between the end 28 and the conductor 12.

After the terminal 24 has been crimped to the conductor 12, the conductor with its attached terminal is placed over the section 22 of the brush holder 14 as is illustrated in FIGURE 3. The welding electrodes 34 and 36 are then brought into engagement respectively with the section 32 of the terminal and the portion 22 of the brush holder and a welding current is then passed through the section 32, through the brush shunt conductor 12 and through the portion 22 of the brush holder from a source of welding current 38. It will be readily apparent to those skilled in the art that by passing a welding current through the portion 32, the brush shunt conductor 12 and the portion 22 of the brush holder, the portion 32, brush shunt conductor 12 and a part of the section'22 of the brush holder will all be welded together.

Referring now to FIGURE 4, it is seen that the brush holder 14 is secured to the frame 40 of a dynamoelectric machine by a rivet The brush Ill is urged into engagement with a commutator 44 by a spring 46 which is enclosed within the rectangular chamber of the brush holder 14. It is seen that the brush holder 14 is in direct metal to metal contact with the frame 40 and this will be the ground connection on the dynamoelectric machine. It pointed out that the end 30 of the ferrule portion 26 will prevent stressing of the weld between the brush shunt conductor 12 and the brush holder. This is true since any movement of the brush shunt conductor 12 which wound tend to stress the weld will be taken up by the end 39 of the ferrule portion 26. This is an important feature of this invention since it prevents stressing of the weld and therefore failure of the welded connection between the brush shunt conductor 12 and the brush holder 14. The particular construction of terminal 24 acts to spread bending stress where the conductor emerges from the connection with the brush holder.

The method of welding illustrated in FIGURE 3 has advantages in that the welding electrode 34 contacts the section 32 of the terminal 24 rather than directly contacting the brush shunt conductor 12 during the welding operation. This reduces flattening out of the brush shunt conductor 12 which could cause a fragile weld between the brush shunt conductor 12 and the brush holder 14.

Referring now more particularly to FIGURE 5, a modified arrangement for forming a welded connection between a brush holder and a brush shunt conductor is illustrated. In FIGURE 5, the reference numeral 14a has been used to designate a brush holder which is identical to the brush holder 14 with one exception. The arcuately extending portion 22a of the brush holder shown in FIGURE 5 has an integral ferrule portion 48 which is identical to the ferrule 26 illustrated in FIGURES 1 and 2. In the embodiment of FIGURE 5, the wire is slipped through the integral ferrule portion 48 so that a portion of the conductor 12a overlies the portion 22a of the brush holder 14a. The brush shunt conductor 12a is then welded directly to the portion 22a at a point designated by reference numeral 50.

between the brush shunt 12 or 12a and the brush holder is illustrated in FIGURE 3, but it is apparent that the construction of FIGURE 5 could be used. It will also be apparent that the terminal 24 could be inverted in FIGURE 3 so that the brush shunt 12 would be contacted by the welding electrode 34 during the welding operation. It is also apparent that the terminal 24 could be welded to the underside of portion 22 of the brush holder with the brush shunt 12 contacting the portion 22.

As has been noted hereinbefore, it is preferred that the flat section 32 will contact the welding electrode rather than the welding electrode directly contacting the brush shunt in making the weld.

While the embodiments of the present invention as herein disclosed constitute preferred forms, it is to be understood that other forms might be adopted.

What is claimed is as follows:

1. In combination, a brush holder, a brush slidable in said brush holder, a brush shunt conductor connected with said brush, and a terminal fitted to said brush shunt conductor including a ferrule portion encircling a part of said brush shunt conductor and a flat section extending coextensively with at least a portion of said brush shunt conductor, said fiat section and a portion of said brush shunt. conductor being welded to said brush holder and said ferrule portion preventing stressing of said welded portion during movement of said conductor.

2. In combination, a brush holder, said brush holder having a section terminating in an integral ferrule portion, and a conductor extending through said ferrule portion having a portion spaced from said ferrule portion welded to said brush holder.

3. In combination, a brush holder having an arcuately extending section and a brush holding portion extending generally radially from said arcuately extending section,

a brush in said brush holding chamber, a brush shunt conductor connected with said brush and welded to the arcuately extending portion of said brush holder, and

means supported by the arcuately extending portion of said brush holder and encircling said brush shunt conductor for preventing stressing of the weld between said conductor and the arcuately extending portion of said brush holder when said conductor is moved.

4. In combination, a metal member, a conductor, means electrically connecting said conductor with said metal member, and means for preventing stressing of the connection of said conductor with said metal member, said last named means including means supported by said metal member having a ferrule portion encircling said conductor, said ferrule portion having a part engaging said conductor and another part that has clearance with said conductor.

5. A terminal connection comprising, a terminal having a substantially flat section and an integral ferrule section, a conductor located within said ferrule section and welded to said flat section, said ferrule section having a portion engaging said conductor which is spaced from the point where said conductor is welded to said flat section and having another portion that has clearance with said conductor.

6. A terminal connection comprising, a terminal having a ferrule section and an integral section extending axially from said ferrule section, and a conductor welded to said axially extending section and passing through said ferrule section, said ferrule section having a part engaging said conductor and another part that has clearance with said conductor.

7. A terminal connection comprising, a terminal having a split ferrule section and an integral axially extending support section, and a conductor welded to said support section and passing through said ferrule section, one end of said ferrule section engaging said conductor, the opposite end of said ferrule section having clearance with said conductor.

References Qited in the file of this patent UNITED STATES PATENTS 2,186,240 Fockler Ian. 9, 1940 2,631,252 Falcettoni' Mar. 10, 1953 2,727,165 Schatfer Dec. 13, 1955 2,760,179 Schaefer Aug. 21, 1956 2,801,402 Barnes July 30, 1957 2,927,230 Guarnier Mar. 1, 1960 3,051,809 Dell Aug. 28, 1962 

1. IN COMBINATION, A BRUSH HOLDER, A BRUSH SLIDABLE IN SAID BRUSH HOLDER, A BRUSH SHUNT CONDUCTOR CONNECTED WITH SAID BRUSH, AND A TERMINAL FITTED TO SAID BRUSH SHUNT CONDUCTOR INCLUDING A FERRULE PORTION ENCIRCLING A PART OF SAID BRUSH SHUNT CONDUCTOR AND A FLAT SECTION EXTENDING COEXTENSIVELY WITH AT LEAST A PORTION OF SAID BRUSH SHUNT CONDUCTOR, SAID FLAT SECTION AND A PORTION OF SAID BRUSH SHUNT CONDUCTOR BEING WELDED TO SAID BRUSH HOLDER AND 